Lymphocytic Choriomeningitis Virus (LCMV)

technical sheet

Classification Diagnosis RNA virus, enveloped Diagnosis is best accomplished through serology, but this is of limited value in an endemically infected colony. Family MAP (mouse antibody production) testing or PCR Arenaviridae testing can be of use in these cases, as can exposure of known naïve adult mice to a suspect colony. These Affected species naïve adults will seroconvert, and then IFA, MFIA™ or Natural LCMV reservoirs are laboratory and wild mice. ELISA can be used to detect antibodies. Most rodents are susceptible to infection, with hamsters Interference with Research especially sensitive to infection, while rats are naturally resistant. LCMV is zoonotic. Pregnant women are especially The most important affect on research associated with susceptible, with adverse fetal outcomes possible. an LCMV-infected colony is the potential infection of workers. LCMV frequently contaminates transplantable Frequency tumors in the mouse, hamster, and guinea pig, tissue Rare among laboratory mice; sporadic among wild cultures, viral stocks (leukaemia virus, rabies virus, mouse populations. PVM...), and sub-strains of Toxoplasma gondii. LCMV has numerous effects on the immune system. Infection Transmission with LCMV inhibits tumor induction due to polyoma virus, and mammary tumor virus in the mouse, and LCMV may be transmitted thorough contact with interferes with transplantable leukaemia in the guinea saliva, nasal secretions, or urine. In natural infections pig and the mouse. Infection is associated with of immunocompetent animals, virus is only shed by depression of cellular immunity in the mouse. Rejection hamsters and mice infected prior to weaning. Among of cutaneous grafts or transplantable tumors may be enzootically infected populations of mice, the most delayed. In addition, infection will increase the sensivity common route of transmission is in utero. of the mouse to ectromelia virus and to bacterial endotoxins. Clinical Signs and Lesions The reaction of laboratory mice to infection with LCMV Prevention and Treatment depends upon age, viral strain, and route of exposure. All mice and hamsters entering a research facility Naturally infected mice do not generally present clinical should be shown to be free of LCMV. Wild mice should signs. Animals infected in utero are tolerant to the be excluded from the facility. All murine-derived virus, which results in systemic, persistent subclinical biological products such as tumors, serum, or cell lines infection. In utero infected animals are often runted as should be tested for the presence of viral contaminants well, due to general effects of this subclinical infection before being used in mouse facilities or the laboratory. on body systems. In the adult mouse, experimental Experimental animals containing tumor transplants, infection results in an acute immune-mediated disease cell line injections, or murine-derived product injections after one week of incubation. Lesions seen in natural should be housed away from breeding animals. Testing LCMV infection are minimal, and are most likely to be for antibodies to LCMV should be part of regular health found in aged animals from the colony. These lesions monitoring of any laboratory mouse colony. include the characteristic lymphocytic choriomeningitis (and lymphocytic infiltrates in liver, adrenal, kidney, If an infection with LCMV is diagnosed, all animals in and lung), immune-complex glomerulonephritis, and the colony must be euthanized. If the source of infection vasculitis. is a cell line or transplantable tumor, it must also be technical sheet

destroyed. The animal house must be cleaned and References disinfected. As an enveloped virus, it probably does not Baker DG. Natural Pathogens of Laboratory Animals: Their effects remain infectious in the environment for more than a few on research. Washington, D.C.: ASM Press; 2003. 385 pp. days and is susceptible to detergents, disinfectants, Fox JG, Anderson LC, Lowe FM, and Quimby FW, editors. drying, and ethanol. All other animal house materials Laboratory Animal Medicine. 2nd ed. San Diego: Academic Press; should be discarded as hazardous waste (incinerated) 2002. 1325 pp. or autoclaved. Hysterectomy rederivation is not effective due to vertical transmission. The virus infects female Fox J, Barthold S, Davisson M, Newcomer C, Quimby F, and Smith A, editors. The Mouse in Biomedical Research: Diseases. germ cells, and may contaminate sperm. If embryo 2nd ed. New York: Academic Press; 2007. 756 pp. transfer is used to attempt to clean a colony, the animals should be followed with PCR testing to detect any Percy DH, Barthold SW. Pathology of Laboratory Rodents and persistently infected animals. Rabbits. Ames: Iowa State University Press; 2007. 325 pp.

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